Method of producing towline plugs



Jan. 30, i v I v z METHOD OF PRODUCING TOW LINE PLUGS Filed May 10,-1944 Patented Jan. 30, 1945 UNITED STATE-s" OFF C I 2368,38; I METHOD OFraonoomor 'rowmnn PLUGS I Aurel Vaszin, Dayton, Ohio Application: Mayit, 1944,.ser iarNo 534.356 a 2 Claims. (ems-r48? This invention relatesto a method of producing a release plug and more particularly to themethod of manufacturing a release plug adapted for use in tow lines fortowing gliders, targets and the like by airplanes.

An object of this invention is to provide a method of producing a towline plug from a forging wherein the tow line plug has a pair of eyes orloops joined by a plate member having at least one face thereofconically shaped and provided with finished marginal portions adapted toen' a e a release cylinder.

Another object of this invention is to provide a method for economicallyproducing a tow line plug that issimple in construction yet dfiaendableand efficient.

Other objects and advantages reside in the con.-

struction of parts; the combination thereof and the mode of operation,as will become more apparent from the following description.

Referring to the drawing, Figure 1 is a top plan View of a forging fromwhich the'plug is made before the forging has been finished.

Figure 2 is an end elevational view of the forging shown in Figure 1.

Figure 3 is a side elevational view ing shown in Figure 1.

Figure 4 is a top planview of the plug'after the forging shown in Figure1 has been turned and finished.

Figure 5 is an end view of theplug shown in Figure 4.

Figure 6 is a side elevational view of the plug of the forg issubstantially circular in cross sectional area.

The retaining loop portion l4 has a substantially circular crosssectional area throughout the greater portion of the periphery. A pairof retaining member facets 20 form a dihedral angle of approximately 140with respect to each other.

These facets are engaged by the retaining means mounted in the cylindernot disclosed herein, as

the retaining means does not form a part of this invention. The pieceshown in Figures 1 to 3 the disc-like portion throughout its entiremargin. As may best be seen by referring to Figures 4, 5 and 6, themargin 22 has been turned so as to be cylindrical. The face 24 hasbeen'turned, so has the face 26. In addition to turning the face 24, thecentral .portion 28 has also been turned so as to have a flat areathroughout the entire side with the exception of the island portions 30and 32 surrounding the ends of the loop portion I4. This turningoperation maybe accomplished by machining so as to remove the metalleaving a substantially fiat surface under the loop portion l4. Theseisland portions 30 and 32 help to center the plug in the cylinder, inthat the island portions 30 and 32 are bounded by arcuate margins.island portions provide seats for the cylinder. The concave margins arethe result of thetooling operation. In addition thereto, these islandportions provide reenforcements, reenforcing the disc-like portions Inin the vicinity of the legs of the retaining loop portion 14. The face26 of the disc-like portion '10 terminates in a conical portion 34 thatextends throughout the center of the disc and gives the disc rigidity.

The plug disclosed herein is easily produced by forging and easilymachined, resulting in a strong, homogeneous plug without the use ofplug, which plug is attached to the clevis integral with'the thimble.The plug piece is forged from a bar of steel.

The forged plug is shown in Figures 1 to 3 inclusive and includes adisc-like portion l0 merging into a loop portion l2 on one side and aretaining loop portion [4 on the opposite side of the disc-like portionIn. The sides of the forged disc-like portion l0 taper, so as to provideconical portions [6 and IS. The loop portion I2 welding and without theuse of a plurality of parts. 'The forging, after it has been machined,

maybe either annealed or tempered or otherwise heat-treated, so as tohavethe proper hardness.

For the purpose of preservation, the finished article may be cadmiumplated, zinc plated or otherwise coated. I

Although the preferred embodiment of the device has been described, itwill be understood that within the purview of this invention variouschanges may bemade in the form, details, pro- The convex margins of theturning the periphery of the disc-like portion so l as to provide acylindrical surface, turning the margin of one side of thedisc-likeportion leaving a conical portion in the center thereof, and

said side, the islands being provided with cylinder-engag'ing convexsurfaces.

2. The process of producing a tow line plug adapted to engage aretaining cylinder provided with releasing means, the process includingthe steps of forging from bar stock a disc-like portion provided withapair of oppositely disposed loops,

forging a pair of facets on one of the loops forming a dihedral angle of140, turning the periphery'of the disc-like portion so as to provideacylindrical surface, turning the margin of one side of the disc-likeportion, leaving a conical portion in the center thereof, and machiningthe opposite side of the disc-like portion by removal of metal leavinga, pair of islands integral with the legs of the loop extending fromsaid side, the

machining the opposite side of the disc-like por-' tion by removal ofmetal leaving a pair of islands islands being provided withcylinder-engaging convex surfaces.

integral with the legs of the loop extending from AUREL VASZIN.

